Integration of iii-v devices on si wafers

ABSTRACT

An insulating layer is conformally deposited on a plurality of mesa structures in a trench on a substrate. The insulating layer fills a space outside the mesa structures. A nucleation layer is deposited on the mesa structures. A III-V material layer is deposited on the nucleation layer. The III-V material layer is laterally grown over the insulating layer.

This patent application is a continuation of co-pending U.S. applicationSer. No. 14/908,112 filed Jan. 27, 2016, which is a U.S. National PhaseApplication under 35 U.S.C. §371 of International Application No.PCT/US2013/062481, filed Sep. 27, 2013, entitled “INTEGRATION OF III-VDEVICES ON SI WAFERS”.

TECHNICAL FIELD

Embodiments as described herein relate to the field of electronicsystems manufacturing, and in particular, to manufacturing III-Vmaterial based devices.

BACKGROUND ART

Generally, to integrate III-V materials on a silicon (“Si”) substratealigned along a <100> crystal orientation (“Si (100)”) forsystem-on-chip (“SoC”) high voltage and radio frequency (“RF”) deviceswith Complementary Metal Oxide Semiconductor (“CMOS”) transistors, greatchallenges arise due to dissimilar lattice properties of the III-Vmaterials and silicon. Typically, when a III-V material is grown on asilicon (“Si”) substrate defects are generated due to the latticemismatch between the III-V material and Si. These defects can reduce themobility of carriers (e.g., electrons, holes, or both) in the III-Vmaterials.

Currently, integration of GaN (or any other III-N material) on Si (100)wafer involves the use of thick buffer layers (>1.5 um) and startingmiscut Si (100) wafer with 2-8° miscut angle to obtain a low enoughdefect density layer for the growth of the device layers. Typically,integration of GaN (or any other III-N material) on Si (100) waferinvolves a blanket epitaxial growth process which occurs over the entirewafer and is not selective area or pattern specific. Additionally,current techniques do not provide a pathway for co-integration of bothGaN transistors and Si CMOS circuits in close proximity to each other.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional view of an electronic device structureaccording to one embodiment.

FIG. 2 is a view similar to FIG. 1, after the portions of the insulatinglayer and substrate are removed according to one embodiment.

FIG. 3 is a view similar to FIG. 2, after a patterned hard mask layer isformed on a bottom of trench according to one embodiment.

FIG. 4 is a view similar to FIG. 3, after the substrate is etchedthrough the patterned hard mask layer to form a plurality of mesastructures according to one embodiment.

FIG. 5 is a view similar to FIG. 4, after an insulating layer isconformally deposited on patterned hard mask layer on the mesastructures in a trench on a substrate according to one embodiment.

FIG. 6 is a view similar to FIG. 5, after the portions of insulatinglayer on top hard mask are removed to expose top surfaces of the mesastructures according to one embodiment.

FIG. 7 is a view similar to FIG. 6, after a nucleation layer isdeposited on the top surfaces of the mesa structures according to oneembodiment.

FIG. 8 is a view similar to FIG. 7, after depositing a III-V materiallayer on the nucleation layer according to one embodiment.

FIG. 9 is a view similar to FIG. 8, after a device layer is depositedover the LEO portions of the III-V material layer according to oneembodiment.

FIG. 10 is a view similar to FIG. 9, after contacts are formed over theportions of device layer over the LEO portions of the III-V materiallayer to form one or more III-V material based devices according to oneembodiment.

FIG. 11 is a three dimensional view of an electronic device structure across-sectional portion of which is depicted in FIG. 2.

FIG. 12 is a cross-sectional view similar to FIG. 9 that shows treadingdislocations generated above mesa structures according to oneembodiment.

FIG. 13 is a cross-sectional view of a portion of a structure shown inFIG. 12 to demonstrate dependence of the defect density from the size ofthe mesa structure according to one embodiment.

FIG. 14 is a cross-sectional view of a portion of a structure shown inFIG. 12 to demonstrate advantages of depositing the LEO portions of theIII-V material layer on the insulating layer 111 according to oneembodiment.

FIG. 15A is a cross-sectional view 1500 of a portion of a structureshown in FIG. 14 to demonstrate lateral overgrowth of the III-V materiallayer according to one embodiment.

FIG. 15B is a view illustrating examples of silicon mesa structuresorientation on a silicon wafer according to one embodiment.

FIG. 16 is a cross-sectional view similar to FIG. 12 to demonstrate twoapproaching LEO portions of the III-V material layer according to oneembodiment.

FIG. 17A shows a cross-sectional view of a III-V material buffer layerstack grown on a planar silicon substrate according to one embodiment.

FIG. 17B shows a cross-sectional view similar to FIG. 12 to demonstrategrowth of the GaN on Si mesas with the reduced buffer thicknesscomparing to the structure shown in FIG. 17A according to oneembodiment.

FIG. 17C is an atomic force microscope view of a portion of thestructure depicted in FIG. 17B.

FIG. 18A is a top view showing a III-V material stack structure grown ona planar substrate according to one embodiment.

FIG. 18B is a top view showing a III-V material stack structure grown onmesa structures according to one embodiment.

FIG. 18C is a graph showing a current versus a voltage curves for a GaNtransistor grown using silicon mesas according to one embodiment.

FIG. 19A shows a cross-sectional view 1901 similar to FIG. 12 todemonstrate seamless merging of the LEO portions of the III-V materiallayer according to one embodiment.

FIG. 19B is a top view of the portion made by a scanning electronmicroscope (“SEM”).

FIG. 19C is an atomic force microscope image of a top view of thestructure having the portions of the GaN material laterally grown overan insulating layer between silicon mesas according to one embodiment.

FIG. 20 illustrates a computing device in accordance with oneembodiment.

FIG. 21A is a view similar to FIG. 4, after an insulating layer isconformally deposited on the patterned hard mask layer on the mesastructures in a trench on a substrate according to one embodiment.

FIG. 21B is a view similar to FIG. 21A, after the insulating layer onthe hard mask is removed according to one embodiment.

FIG. 22 is a view similar to FIG. 21B, after a nucleation layer isdeposited on the top surfaces of the mesa structures according to oneembodiment.

FIG. 23 is a view similar to FIG. 22, after depositing a device layer ona III-V material layer on the nucleation layer according to oneembodiment.

DESCRIPTION OF THE EMBODIMENTS

In the following description, numerous specific details, such asspecific materials, dimensions of the elements, etc. are set forth inorder to provide thorough understanding of one or more of theembodiments as described herein. It will be apparent, however, to one ofordinary skill in the art that the one or more embodiments as describedherein may be practiced without these specific details. In otherinstances, semiconductor fabrication processes, techniques, materials,equipment, etc., have not been described in great detail to avoidunnecessary obscuring of this description.

While certain exemplary embodiments are described and shown in theaccompanying drawings, it is to be understood that such embodiments aremerely illustrative and not restrictive, and that the embodiments arenot restricted to the specific constructions and arrangements shown anddescribed because modifications may occur to those ordinarily skilled inthe art.

Reference throughout the specification to “one embodiment”, “anotherembodiment”, or “an embodiment” means that a particular feature,structure, or characteristic described in connection with the embodimentis included in at least one embodiment. Thus, the appearance of thephrases, such as “one embodiment” and “an embodiment” in various placesthroughout the specification are not necessarily all referring to thesame embodiment. Furthermore, the particular features, structures, orcharacteristics may be combined in any suitable manner in one or moreembodiments.

Moreover, inventive aspects lie in less than all the features of asingle disclosed embodiment. Thus, the claims following the DetailedDescription are hereby expressly incorporated into this DetailedDescription, with each claim standing on its own as a separateembodiment. While the exemplary embodiments have been described herein,those skilled in the art will recognize that these exemplary embodimentscan be practiced with modification and alteration as described herein.The description is thus to be regarded as illustrative rather thanlimiting.

Methods and apparatuses to manufacture an electronic device aredescribed herein. An insulating layer is conformally deposited on aplurality of mesa structures in a trench on a substrate. The insulatinglayer fills a space outside the mesa structures. A nucleation layer isdeposited on the mesa structures. A III-V material layer is deposited onthe nucleation layer. The III-V material layer is laterally grown overthe insulating layer.

Generally, the III-V material refers to a compound semiconductormaterial that comprises at least one of group III elements of theperiodic table, e.g., aluminum (“Al”), gallium (“Ga”), indium (“In”),and at least one of group V elements of the periodic table, e.g.,nitrogen (“N”), phosphorus (“P”), arsenic (“As”), antimony (“Sb”). In atleast some embodiments, the substrate includes silicon, and the III-Vlayer includes GaN.

In at least some embodiments, methods to co-integrate GaN devices (e.g.,transistors, and other GaN based devices) for power managementintegrated circuits (“PMIC”) and RF power amplifier (“PA”) applicationsin close proximity to Si Complementary Metal Oxide Semiconductor(“CMOS”) circuits for system on chip (“SoC”) products are described. Inat least some embodiments, an electronic device, e.g., a transistor, orany other electronic device comprising an epitaxially grown III-Nitride(“N”) material is formed within small islands embedded in a Si waferaligned along (100) crystallographical orientation. Forming anelectronic device in the islands embedded in a Si wafer aligned along(100) crystallographical orientation allow the co-integration of theIII-V material based transistors with both low defect density and lowbody leakage alongside Si CMOS circuits.

In an embodiment, to integrate GaN on Si (100) for SoC high voltage andRF devices in close proximity of CMOS transistors, GaN transistor stackis grown selectively inside predefined trenches within the Si CMOSwafer. From a device standpoint, the size of the each side of the trenchis from about 70 microns (“μm”) to about 100 μm. Within the trenches theuse of an oxide underlayer allows the implementation of lateralepitaxial overgrowth (“LEO”) of GaN resulting in low defect density andlow body leakage for the GaN device. In an embodiment, the Si mesasformed break up the continuity of the Si film at the bottom of thetrench in the Si substrate that allows to reduce the GaN epitaxial layerstack total thickness comparing to total thickness of the GaN epi stackblanket deposited on the plane Si (100) wafer for the same defect andcrack density.

FIG. 1 shows a cross-sectional view 100 of an electronic devicestructure according to one embodiment. The electronic device structurecomprises a substrate 101. In an embodiment, the substrate 101 is asubstrate having aligned along a predetermined crystal orientation.Generally, the crystallographic orientations (e.g., (100), (111), (110),and other crystallographical orientations) are known to one of ordinaryskill in the art of electronic device manufacturing. In an embodiment,the substrate 101 includes a semiconductor material, e.g.,monocrystalline silicon (“Si”), germanium (“Ge”), silicon germanium(“SiGe”), a III-V materials based material e.g., gallium arsenide(“GaAs”), or any combination thereof. In one embodiment, the substrate101 includes metallization interconnect layers for integrated circuits.In at least some embodiments, the substrate 101 includes electronicdevices, e.g., transistors, memories, capacitors, resistors,optoelectronic devices, switches, and any other active and passiveelectronic devices that are separated by an electrically insulatinglayer, for example, an interlayer dielectric, a trench insulation layer,or any other insulating layer known to one of ordinary skill in the artof the electronic device manufacturing. In at least some embodiments,the substrate 101 includes interconnects, for example, vias, configuredto connect the metallization layers.

In an embodiment, substrate 101 is a semiconductor-on-isolator (SOI)substrate including a bulk lower substrate, a middle insulation layer,and a top monocrystalline layer aligned along a predetermined crystalorientation, for example, <100> crystal orientation. The topmonocrystalline layer may comprise any material listed above, e.g.,silicon.

In an embodiment, substrate 101 is a silicon substrate aligned along a<100> crystal orientation (“Si (100)”). An insulating layer 102 isdeposited on the substrate.

Insulating layer 102 can be any material suitable to insulate adjacentdevices and prevent leakage. In one embodiment, electrically insulatinglayer 102 is an oxide layer, e.g., silicon dioxide, or any otherelectrically insulating layer determined by an electronic device design.In one embodiment, insulating layer 102 comprises an interlayerdielectric (ILD), e.g., silicon dioxide. In one embodiment, insulatinglayer 102 may include polyimide, epoxy, photodefinable materials, suchas benzocyclobutene (BCB), and WPR-series materials, or spin-on-glass.In one embodiment, insulating layer 102 is a low permittivity (low-k)ILD layer. Typically, low-k is referred to the dielectrics havingdielectric constant (permittivity k) lower than the permittivity ofsilicon dioxide.

In one embodiment, insulating layer 102 is a shallow trench isolation(STI) layer to provide field isolation regions that isolate one islandfrom other islands on substrate 101. In one embodiment, the thickness ofthe layer 102 is in the approximate range of 20 nanometers (“nm”) to 350nanometers. The insulating layer 102 can be blanket deposited using anyof techniques known to one of ordinary skill in the art of electronicdevice manufacturing, such as but not limited to a chemical vapourdeposition (CVD), and a physical vapour deposition (PVD). A patternedlayer 103 is formed on the insulating layer 102 to expose portions ofthe insulating layer 102. In an embodiment, layer 103 is a patternedhard mask layer. The hard mask layer can be patterned using one ofpatterning and etching techniques known to one of ordinary skill in theart of electronic device manufacturing. In at least some embodiments,hard mask layer 103 comprises an aluminum oxide (e.g., Al2O3);polysilicon, amorphous Silicon, poly germanium (“Ge”), a refractorymetal (e.g., tungsten (“W”), molybdenum (“Mo”), or other refractorymetal), or any combination thereof. In an embodiment, layer 103 is aphotoresist layer.

FIG. 2 is a view 200 similar to FIG. 1, after the portions of theinsulating layer and substrate are removed according to one embodiment.A portion of the insulating layer 102 exposed by hard mask 103 isremoved to expose substrate 101. The portion of the insulating layer 102can be removed using an etching technique known to one of ordinary skillin the art of electronic device manufacturing, such as but not limitedto a wet etching, and a dry etching. In an embodiment, insulating layer104 of silicon oxide is etched using a hydrofluoric acid (“HF”)solution.

As shown in FIG. 2, a portion of substrate 101 exposed by insulatinglayer 102 is removed to form a trench 104. Trench has a depth 201 and awidth 127. In an embodiment, depth 201 is from about 2 microns (“μm”) toabout 3 μm, and width 127 is in from about 20 μm to about 500 μm. In oneembodiment, the portion of substrate 101 is etched using one or moreetching techniques known to one of ordinary skill in the art ofelectronic device manufacturing. In an embodiment, an etching solution(e.g., tetramethylammonium hydroxide (“TMAH”), potassium hydroxide(“KOH”), ammonium hydroxide (“NH4OH”)) is used to anisotropically etchthe Si substrate. In an embodiment, a dry etch using gases SF6, XeF2,BCl3, Cl2, or any combination thereof is used to etch the siliconsubstrate.

As shown in FIG. 2, hard mask 103 is removed from insulating layer 102.The hard mask can be removed from the insulating layer by a polishingprocess, such as a chemical-mechanical planarization (“CMP”) process asknown to one of ordinary skill in the art of electronic devicemanufacturing.

FIG. 11 is a three dimensional (“3D”) view of an electronic devicestructure a cross-sectional portion of which is depicted in FIG. 2. Asshown in FIG. 11, insulating layer 102 is deposited on substrate 101.Trenches, such as trenches 104 and 123 are formed through insulatinglayer 102 in the substrate 101, as described above. Trench 104 has alength 122 and width 127. In an embodiment, length 122 is from about 50μm to about 100 μm, and width 127 is from about 50 μm to about 100 μm.In at least some embodiments, trenches 104 and 123 comprise islandswhere III-V materials based devices are formed as described in furtherdetail below. In at least some embodiments, insulating layer 102 coversCMOS device areas on substrate 101. In at least some embodiments, thetrenches, such as trenches 104 and 123 are created within the Si CMOSwafer prior to Si CMOS processing. In at least some embodiments, thetrenches, such as trenches 104 and 123 are predefined by a circuitdesigner.

FIG. 3 is a view 300 similar to FIG. 2, after a patterned hard masklayer 105 is formed on a bottom 301 of trench 104 according to oneembodiment. The hard mask layer 105 deposited on bottom 301 of trench104 can be patterned using one of patterning and etching techniquesknown to one of ordinary skill in the art of electronic devicemanufacturing. In at least some embodiments, hard mask layer 105comprises an aluminum oxide (e.g., Al₂O₃); polysilicon, amorphousSilicon, poly germanium (“Ge”), a refractory metal (e.g., tungsten(“W”), molybdenum (“Mo”), or other refractory metal), or any combinationthereof.

FIG. 4 is a view 400 similar to FIG. 3, after the substrate is etchedthrough the patterned hard mask layer 105 to form a plurality of mesastructures, such as a mesa structure 106 and a mesa structure 107according to one embodiment. As shown in FIG. 4, the mesa structureshave the height, such as a height 110 and the width, such as a width108. In at least some embodiments, the height of the mesa structure isfrom about 100 nm to about 500 nm. In at least some embodiments, thewidth of the mesa structure is from about 5 μm to about 10 μm. Mesastructures are separated by a distance 109. In at least someembodiments, the distance between the mesa structures is predeterminedby a ratio of a lateral overgrowth rate to a vertical growth rate of theIII-V material layer formed over the mesa structures later on in aprocess. For example, if the ratio of a lateral overgrowth rate to avertical growth rate of the III-V material layer is about 10:1, and thethickness of the III-V material layer is about 1 μm, the distancebetween the mesa structures is about 20 μm. In at least someembodiments, the distance between the mesa structures is from about 1 μmto about 50 μm.

The mesa structures can have a square shape; a rectangular shape, apolygon shape, or any combination thereof.

In an embodiment, within the trenches on the silicon substrate, such astrench 104, there are several silicon mesa structures with exposedsilicon surface for III-Nitride (“N”) epitaxy. These mesa structures maybe square, rectangular or shaped like a polygon and could be oriented invarious directions for efficient III-N lateral growth.

In one embodiment, the mesa structures are formed using one or moreetching techniques known to one of ordinary skill in the art ofelectronic device manufacturing. In an embodiment, the mesa structuresare formed by etching the portions of Si substrate exposed by patternedhard mask layer within trench using an etching solution (e.g.,tetramethylammonium hydroxide (“TMAH”), potassium hydroxide (“KOH”),ammonium hydroxide (“NH4OH”)). In an embodiment, the mesa structures areformed by dry etching the portions of Si substrate exposed by patternedhard mask layer within trench using gases SF6, XeF2, BCl3, Cl2, or anycombination thereof. In an embodiment, the mesa structure 104 isoriented along a predetermined crystallographical direction.

FIG. 15B is a view 1510 illustrating examples of silicon mesa structuresorientation on a silicon wafer 1501 according to one embodiment. Asshown in FIG. 15B, there are different crystallographical directions onSi (100) wafer 1501, such as directions 1502, 1503, and 1504. Each ofthe mesa structures can be aligned along one of these directions. In anembodiment, the mesa structure 104 is aligned along <110>crystallographical direction. In an embodiment, the mesa structure 104is aligned along <100> crystallographical direction. In an embodiment,the mesa structure 104 is aligned along <010> crystallographicaldirection.

FIG. 5 is a view 500 similar to FIG. 4, after an insulating layer 111 isconformally deposited on patterned hard mask layer 105 on the mesastructures in a trench on a substrate according to one embodiment. Theinsulating layer 111 fills the space outside the mesa structures andcovers the sidewalls of the trench. As shown in FIG. 5, insulating layerfills the space between mesa structures 106 and 107, between the mesastructure 106 and a sidewall 112 of the trench 104, and between the mesastructure 107 and a sidewall 113 of the trench 104. Insulating layer 111covers sidewall 112 and sidewall 113 of the trench. In an embodiment,insulating layer 111 is a silicon oxide (e.g. SiO₂) layer, a siliconnitride layer, aluminum oxide (“Al₂O₃”), silicon oxide nitride (“SiON”),other oxide/nitride layer, any combination thereof, or otherelectrically insulating layer determined by an electronic device design.In an embodiment, the thickness of the insulating layer 111 is fromabout 100 nm to about 500 nm. In an embodiment, the entire trench 104 islined by a thin (from about 50 to about 100 nm) oxide or nitride layer.The nitride/oxide layer also fills up the region between the siliconmesas. In one embodiment, insulating layer 111 comprises an interlayerdielectric (ILD), e.g., silicon dioxide. In one embodiment, insulatinglayer 111 is a low permittivity (low-k) ILD layer. Typically, low-k isreferred to the dielectrics having dielectric constant (permittivity k)lower than the permittivity of silicon dioxide.

The insulating layer 111 can be conformally deposited over the mesastructures using any of conformal deposition techniques, such as but notlimited to a chemical vapour deposition (CVD), and a physical vapourdeposition (PVD), molecular beam epitaxy (“MBE”), metalorganic chemicalvapor deposition (“MOCVD”), atomic layer deposition (“ALD”), or otherconformal growth technique known to one of ordinary skill in the art ofelectronic device manufacturing. In an embodiment, insulating layer 111is conformally deposited over the mesa structures using low temperatureCVD processes.

FIG. 6 is a view 600 similar to FIG. 5, after the portions of insulatinglayer 111 on top hard mask 105 are removed to expose top surfaces 114 ofthe mesa structures according to one embodiment. In an embodiment, hardmask 105 underneath insulating layer 111 is selectively wet etched toundercut the hard mask layer. Insulating layer 111 is removed bylifting-off the undercut hard mask 105 to expose the top surfaces 114 ofthe mesa structures. In an embodiment, hard mask 105 is selectively wetetched using an acid based chemistry. As an example, when hard mask 105is tungsten (“W”) and insulating layer 111 is SiO₂, then the hard maskof W can be wet etched in a wet etch solution comprising a ratio of 1:2of NH₄OH:H₂O₂ selectively to the SiO₂ insulating layer.

FIG. 7 is a view 700 similar to FIG. 6, after a nucleation layer isdeposited on the top surfaces of the mesa structures according to oneembodiment. As shown in FIG. 7, a nucleation layer 115 is selectivelydeposited onto the top surfaces of the mesa structures 107 and 106. Inan embodiment, nucleation layer 115 is an aluminum nitride (“AlN”)layer. The nucleation layer 115 can be deposited using one of epitaxialtechniques, e.g., chemical vapor deposition (“CVD”), metalorganicchemical vapor deposition (“MOCVD”), atomic layer deposition (“ALD”),molecular beam epitaxy (“MBE”), or other epitaxial growth techniqueknown to one of ordinary skill in the art of electronic devicemanufacturing.

In an embodiment, the nucleation layer 115 is deposited using a MOCVDtechnique at a temperature above 1000° C. In an embodiment, thenucleation layer 115 is deposited using a MBE technique at a temperaturefrom about 750° C. to about 800° C. In an embodiment, the nucleationlayer of aluminum nitride (“AlN”) is deposited onto the top surfaces ofthe mesa structures to the thickness from about 5 nm to about 200 nm. Inan embodiment, nucleation layer 115 of AlN is used to prevent theformation of group III elements and silicon (e.g., GaSi) complexes thatcan be formed if the III-V material layer is deposited directly onto thesilicon. In an embodiment, nucleation layer 115 is used to provide aseed hexagonal crystal structure for the III-V material layer formed onthe nucleation layer later on in a process. In an embodiment, nucleationlayer 115 is used to capture the interface defects that are formed dueto the lattice mismatch between III-V material and silicon.

FIG. 8 is a view 800 similar to FIG. 7, after depositing a III-Vmaterial layer on the nucleation layer according to one embodiment. AIII-V material layer 116 is selectively deposited on nucleation layer115. The III-V material layer 116 is laterally grown over the portions801, 802, and 803 of the insulating layer 111 outside the mesastructures 106 and 107, to form LEO portions, such as LEO portions 811,812, and 813 as shown in FIG. 8.

In an embodiment, III-V material layer 116 is locally grown onnucleation layer 115 using a selective area epitaxy. III-V materiallayer 116 can be selectively deposited using one of epitaxial techniquesknown to one of ordinary skill in the art of electronic devicemanufacturing, e.g., chemical vapor deposition (“CVD”), metallo organicchemical vapor deposition (“MOCVD”), atomic layer deposition (“ALD”), orother epitaxial growth technique known to one of ordinary skill in theart of electronic device manufacturing.

In an embodiment, the III-V material layer 116 is grown vertically onnucleation layer 115 using a MOCVD technique at a temperature in anapproximate range of 1000 C-1100° C. In an embodiment, the III-Vmaterial layer grown on nucleation layer 115 expands in lateraldirection over the insulating layer 111 by modifying at least one of theepitaxial growth parameters, such as a temperature, pressure. In anembodiment, a ratio of the LEO rate to the vertical growth rate of theIII-V material layer is at least 5. In an embodiment, the III-V materiallayer 116 expands in the lateral direction over the insulating layer 111by increasing the temperature above 1100° C. In an embodiment, the III-Vmaterial layer 116 expands in the lateral direction over the insulatinglayer 111 by decreasing the pressure in the growth chamber down to below200 Torr, and more specifically, to about 50 Torr. In an embodiment, theIII-V material layer 116 expands in the lateral direction over theinsulating layer 111 by adding chemical elements (e.g., magnesium(“Mg”), antimony (“Sb”), indium (“In”), or other chemical elements) intothe grown chamber reduce the vertical growth rate relative to thelateral growth rate. These chemical elements act as surfactants thatattach to the top surface of the silicon mesa structures during theIII-V material layer growth thereby reducing the vertical growth rate ofthe III-V material layer over the silicon mesas. In an embodiment, thegas phase concentration of Mg in the growth chamber during GaN growth isfrom about 1% to about 5% of total Ga gas phase concentration. In anembodiment, the gas phase concentration of Sb in the growth chamberduring GaN growth is from about 0.5% to about 5% of total Ga gas phaseconcentration. In an embodiment, the gas phase concentration of In inthe growth chamber during GaN growth is from about 0.1% to about 5% oftotal Ga gas phase concentration. In an embodiment, III-V material layer116 is GaN, InGaN, any other III-N material, any other III-V material,or any combination thereof. In an embodiment, the thickness of the III-Vmaterial layer 116 is from about 250 nm to about 2 μm.

In an embodiment, the III-N material layer is nucleated on the exposedsurface of the silicon mesa structure, and later with change of growthconditions grows laterally over the oxide/nitride layer. In the nitridematerial system, threading dislocations normally glide along the [0001]direction with a minimal angle, and hence by using lateral growth asubstantially defect free or low defect density GaN film is created.This defect free LEO GaN layer lies on top of the oxide/nitride layerand hence creates a GaN-on-insulator architecture for building GaNtransistors. GaN is wideband gap material (3.4 eV) and combined with theunderlying insulator can lead to extremely low body leakage currents(order of femto to pico amps/mm) for the transistors, which makes itsuitable for RF applications. Although this is a form of epitaxy, whichrequires the use of underlying buffer layers to reduce defect densityand mitigate surface crack formation, the patterning and henceseparating the silicon substrate using multiple mesa structures insidethe trenches leads to reduction of the total thermal stress buildup inthe GaN epi layer. As such, very complicated and thick buffer layers arenot required and zero surface cracks and low defect density are obtainedwith the use of much thinner epi layers.

FIG. 9 is a view 900 similar to FIG. 8, after a device layer 118 isdeposited over the LEO portions of the III-V material layer 116according to one embodiment. In an embodiment, device layer 118 isdeposited on a device layer 117 on III-V material layer 116. In anembodiment, device layer 117 is deposited to enhance mobility in atwo-dimensional electron gas (“2DEG”) portion 120 of the III-V materiallayer 116. In an embodiment, device layer 117 is an AlN layer. In anembodiment, the thickness of the device layer 117 is from about 1 nm toabout 3 nm.

In an embodiment, device layer 118 includes a III-V material, e.g.,AlGaN, AlInN, AlN, any other III-V material, or any combination thereof.In an embodiment, device layer 118 is an Al_(x)Ga_(1-x)N layer, where xis from about 15% to about 40%. In an embodiment, device layer 118 is anAl_(x)In_(1-x)N layer, where x is greater than about 85%. In anembodiment, device layer 118 is an AlN layer. The thickness of thedevice layer 202 determined by a device design. In an embodiment, thethickness of the device layer 202 is from about 2 nm to about 40 nm.

In an embodiment, each of device layers 118 and 117 is deposited usingone of epitaxial growth techniques, e.g., chemical vapor deposition(“CVD”), metallo organic chemical vapor deposition (“MOCVD”), atomiclayer deposition (“ALD”), MBE, or other epitaxial growth technique knownto one of ordinary skill in the art of electronic device manufacturing.

FIG. 10 is a view 1000 similar to FIG. 9, after contacts are formed overthe portions of device layer 118 over the LEO portions of the III-Vmaterial layer 116 to form one or more III-V material based devicesaccording to one embodiment. The III-V material based devices can be,for example, high voltage transistors (e.g., GaN transistors), RF-poweramplifiers, power management integrated circuits, or other III-Vmaterial based electronic devices. As shown in FIG. 10, device contacts121, 131, and 141 are formed on the portions of the device layer overthe LEO portions of the III-V material layer 116. In an embodiment,device contact 121 is a gate electrode over a gate dielectric 151 on thedevice layer 118 over the LEO portion 813 of III-V material layer 116.Contact 141 is a source contact on a source region 161, and contact 131is a drain contact on a drain region 171 of the device layer 118 overthe LEO portion of III-V material layer 118. The contacts 121, 131, and121, gate dielectric 151, drain and source regions 161 and 171 can beformed on the III-V material device layer using techniques known to oneof ordinary skill in the art of electronic device manufacturing.

FIG. 12 is a cross-sectional view 1200 of a structure inside a trenchwhere III-V material based devices can be fabricated similar to FIG. 9that shows treading dislocations 124 generated above mesa structuresaccording to one embodiment. Treading dislocations 124 propagate acrossportions of the III-V material layer 116 at about 90 degree angle to thetop surface of the mesa structures 106 and 107. There are no threadingdislocations across LEO portions 811, 812, and 813. In an embodiment,the LEO portions of the III-V material layer are free of the threadingdislocations.

In an embodiment, the device layer is a GaN layer grown inside aredefined trench formed within a parent Si CMOS wafer. This area iscalled a GaN island and can be used to fabricate a PMIC and RF-PA partof the SoC chip. The trench can be square or rectangular in shape. Thetrench can be oriented along the <110> direction or at a 45 degree angleto <110> direction. In an embodiment, the depth of the trench is about2-3 μm. Inside the trench, silicon mesas are created which can be fromabout 100 nm to about 300 nm tall, as described above.

In an embodiment, the space between the mesas is filled with anoxide/nitride layer and the trench is also lined by that sameoxide/nitride layer, as described above. This oxide/nitride layer actsas a liner on the trench sidewalls to prevent the distortion of theadjacent silicon lattice as the GaN layer grows and stops at the liner.

In an embodiment, when GaN grows laterally over this insulating layer aGaN-on-insulator type of an architecture is created, which leads to verylow body leakage currents in the transistor, an important requirementfor RF applications.

In an embodiment, the III-N material layer epitaxy begins on siliconmesas. The silicon mesa structures are created by patterning siliconwithin the trench, as described above. These mesas provide a startingnucleation for III-N epitaxy. Patterning the silicon substrate to createthe mesa structures leads to reduction of thermal stress in the systemand hence does not necessitate the use of complex buffer layers (whichexist in the current solutions) to reduce surface cracks and defectdensity. The orientation of these silicon mesas and their dimensions areused to control both the surface crack density and defect density of GaNwithin the island.

The device layer 118 is then grown over the entire III-V material layer,as described above. In an embodiment, device layer 118 is a layer whichinduces the 2DEG by polarization. In an embodiment, the device layer 118is an alloy, e.g., AlGaN with an underlying AlN thin spacer, or InAlNwith an underlying AlN thin spacer. In an embodiment, the thickness ofthe AlN spacer is about 1 nm and the thickness one of the AlGaN InAlN isin an approximate range of 2-20 nm.

FIG. 21A is a view 2110 similar to FIG. 4, after an insulating layer 111is conformally deposited on the patterned hard mask layer 105 on themesa structures in a trench on a substrate 101 according to oneembodiment. The insulating layer 111 covers the sidewalls of the mesastructures and the trench and fills the space outside the mesastructures, as described above with respect to FIG. 5. FIG. 21A differsfrom FIG. 5 in that the insulating layer 111 is conformally deposited tothe thickness that is smaller than the height of the mesa structures 106and 107.

FIG. 21B is a view 2100 similar to FIG. 21A, after the insulating layer111 on the hard mask 105 is removed from portions of the mesa structuresaccording to one embodiment. As shown in FIG. 21, the insulating layer111 is removed from portions of the sidewalls 2103 and 2104 of mesastructure 107 and portions of the sidewalls 2101 and 2102 of mesastructure 106. In an embodiment, hard mask 105 underneath insulatinglayer 111 is selectively wet etched to undercut the hard mask layer. Inan embodiment, hard mask 105 is selectively wet etched using an acidbased chemistry, as described above with respect to FIG. 6. In anembodiment, insulating layer 111 is removed by lifting-off the undercuthard mask 105 to expose the top surfaces 114 of the mesa structures andthe portions of the sidewalls of the mesa structures 106 and 107. In anembodiment, the insulating layer 111 is removed from the portions of thesidewalls of mesa structures using one of etching techniques known toone of ordinary skill in the art of electronic device manufacturing,such as but not limited to a wet etching, and a dry etching. In anembodiment, insulating layer 111 of silicon oxide is etched using ahydrofluoric acid (“HF”) solution.

In an embodiment, the height of the exposed portions of the mesastructures, such as a height 2015 is determined by an electronic devicedesign. In an embodiment, the height of the exposed portions of the mesastructures, such as a height 2015 is at least about 100 nm.

FIG. 22 is a view 2200 similar to FIG. 21B, after a nucleation layer isdeposited on the top surfaces of the mesa structures according to oneembodiment. As shown in FIG. 22, a nucleation layer 115 is selectivelydeposited onto the top surfaces of the mesa structures 107 and 106, asdescribed above. In an embodiment, nucleation layer 115 is an aluminumnitride (“AlN”) layer. The nucleation layer 115 can be deposited usingone of epitaxial techniques, as described above.

FIG. 23 is a view 2300 similar to FIG. 22, after depositing a devicelayer 118 on a III-V material layer 116 on the nucleation layer 115according to one embodiment. A III-V material layer 116 is selectivelydeposited on nucleation layer 115. III-V material layer 116 is laterallygrown outside the mesa structures 106 and 107, to form LEO portions,such as LEO portions 811, 812, and 813. As shown in FIG. 23, the LEOportions 811, 812, and 813 are not directly in contact with theinsulating 111 layer and are suspended over the mesa structures 106 and107. As shown in FIG. 23, the LEO portions 811, 812, and 813 areseparated from the insulating layer 111 on substrate 101 by a space,such as a space 2311. In an embodiment, insulating layer 111 is removedfrom the portions of the substrate 101 that are underneath the LEOportions 811, 812, and 813, and the space is created is between thesubstrate and the LEO portions.

In an embodiment, the space is defined by the height of the exposedportion of the sidewall of the mesa structure and the thickness of thenucleation layer 115. In an embodiment, the space 2311 between theinsulating layer and LEO portion is from about 150 nm to about 400 nm.

In an embodiment, III-V material layer 116 is locally grown onnucleation layer 115 using a selective area epitaxy, as described above.In an embodiment, the III-V material layer grown on nucleation layer 115expands in a lateral direction to be suspended over the insulating layer111 by modifying at least one of the epitaxial growth parameters, suchas a temperature, pressure, as described above. In an embodiment, theIII-V material layer 116 expands in the lateral direction to besuspended outside the mesa structures by adding chemical elements intothe grown chamber to reduce the vertical growth rate relative to thelateral growth rate, as described above. As shown in FIG. 23, devicelayer 118 is deposited over III-V material layer 116, as describedabove. In an embodiment, an enhance mobility layer (not shown) isdeposited between the device layer 118 and III-V material layer 116, asdescribed above.

As shown in FIG. 23, treading dislocations 124 propagate across portionsof the III-V material layer 116 at about 90 degree angle to the topsurface of the mesa structures 106 and 107. There are no threadingdislocations across LEO portions 811, 812, and 813. In an embodiment,the LEO portions of the III-V material layer are free of the threadingdislocations. In an embodiment, lateral growth of the wideband gap III-Vmaterial outside the mesa structures which is separated from theunderlying insulator by a space can lead to even lower body leakagecurrents than in the structure depicted in FIG. 9.

FIG. 13 is a cross-sectional view 1300 of a portion of a structure shownin FIG. 12 to demonstrate dependence of the defect density from the sizeof the mesa structure according to one embodiment. Mesa structure 106has a width 126. The mesa structure 106 is separated from another mesastructure (not shown) by distance 109. In an embodiment, as GaNlaterally grows on the oxide layer, it results in low defect density GaNfilms. This is because of the nature of dislocation defects in nitrides,which prefer to thread up almost vertically (along the 0001 direction)and hence do not appear for laterally overgrown GaN on oxide. Thisapproach thus leads to an overall reduction in the defect density of GaNepi films on Si (100). In an embodiment, the total defect density of theIII-V material layer 116 depends on the ratio of the size of the mesastructure (width 126) and distance 109. In an embodiment, the distance109 is about 100 μm, width 126 is about 2 μm provides defect density inthe LEO region of the GaN about 10⁷ cm⁻², and defect density above inthe region of the GaN layer above the mesa structure about 10⁹ cm⁻².Hence, the average defect density in the GaN layer is from about 10⁷cm⁻² to about 2×10⁷ cm⁻².

FIG. 14 is a cross-sectional view 1400 of a portion of a structure shownin FIG. 12 to demonstrate advantages of depositing the LEO portions ofthe III-V material layer 116 on the insulating layer 111 according toone embodiment. As shown in FIG. 14, the insulating layer 111 (e.g.,oxide/nitride) acts a liner to prevent III-V material (e.g., GaN) fromdirect contact with adjacent sidewall 112 of silicon substrate 102 thatcan prevent damage of the silicon substrate 102.

The insulating layer (e.g., oxide/nitride) layer formed between thesilicon mesas provides at least two advantages: a) the insulating layerreduces the body leakage current in the GaN transistor from what itwould have been if the GaN transistor were formed on Si. That is, theinsulating layer 111 provides a III-V material-on-insulator approachsimilar to silicon-on-insulator approach used in RF applications. b) theinsulating layer enables laterally epitaxial overgrowth of the III-Vmaterial. This is further explained with respect to FIG. 15A.

FIG. 15A is a cross-sectional view 1500 of a portion of a structureshown in FIG. 14 to demonstrate lateral overgrowth of the III-V materiallayer according to one embodiment. In an embodiment, when III-V materiallayer 116 (e.g., GaN) grows over the insulating layer 111 (e.g., siliconoxide), the {1-100} facets 129 grow out fast and are called lateralovergrowth as opposed to vertical growth where the {0001} planes 128 aregrown. Due to the nature of the dislocations in nitrides, the threadingdisclocation defects 124 are not present in the LEO GaN region and henceare effectively “trapped” within the region above the silicon mesas.Thus, the LEO GaN films have substantially low defects density and aresubstantially defect free, whereas the GaN layer which grows above themesa structures has threading disclocations 124 and defect density fromabout 1×10⁹ cm⁻² to about 8×10⁹ cm⁻².

FIG. 16 is a cross-sectional view 1600 similar to FIG. 12 to demonstratetwo approaching LEO portions of the III-V material layer according toone embodiment. In an embodiment, patterning of the silicon substrate101 into mesa structures 106 and 107 provide the following advantages:

a) The orientation, size, and shape of the silicon mesa structure areused to enable lateral epitaxial overgrowth of III-V material layer 116(e.g., GaN) and the growth rates of the lateral facets of III-V materiallayer 116. The orientation, size, and shape of the silicon mesastructure are also important for seamless merging of two portions 130and 131 of III-V material layer 116, approaching each other because ofthe LEO growth. The orientation of the silicon mesas 106 and 107determines if the III-V material (e.g., GaN) facets of the portions 130and 131 which overgrow on the insulating layer 111 (e.g., SiO₂) wouldhave substantially vertical planes for seamless merging.

Due to the patterning of the silicon mesas the net thermal stressmismatch between the III-V material layer 116 (e.g., GaN) and siliconsubstrate 101 is partitioned and reduced as compared to the thermalstress developed for a GaN film grown on a continuous Si substrate. Thisis beneficial as the tensile stress developed in the GaN film on Siduring cool down post epitaxy can be huge (about GPa) that leads tosurface crack formation in the GaN epitaxial layer. To alleviate this,typically complex buffer layer stacks are used (current solutions) tocounter balance this tensile stress. By reducing this thermal stress bypatterning the Si substrate into the mesa structures, the need for thiscomplex buffer layer stacks is removed. As such, the total buffer layerthickness can be almost halved while maintaining the same defect densityand substantially zero surface crack density.

FIG. 17A shows a cross-sectional view 1700 of a III-V material bufferlayer stack grown on a planar silicon substrate according to oneembodiment. As shown in FIG. 17A, a thick III-V material stack 1702grown on a planar silicon substrate 1701 contains multiple AlN/GaNlayers (e.g., AlN/GaN/AlN/GaN/AlN/GaN/AlN/GaN/AlN). Typically, thethickness of the III-V material stack 1702 is greater than about 2.5microns.

FIG. 17B shows a cross-sectional view 1710 similar to FIG. 12 todemonstrate growth of the GaN on Si mesas with reduced buffer thicknesscomparing to the structure shown in FIG. 17A according to oneembodiment. As shown in FIG. 17B, LEO portions 1712 of the GaN layer areproduced over the SiO2 insulating layer outside the mesa structures. TheLEO portions 1712 are substantially free of surface cracks, as shown inFIG. 17B. FIG. 17C is an atomic force microscope (“AFM”) view 1720 of aportion 1711 of the structure depicted in FIG. 17B. As shown in FIG.17C, the portion 1711 has LEO portion 1712 with vertical planes forseamless merging with other LEO portions. The AFM view shows highquality GaN grown by lateral overgrowth and seamless merging of the LEOregions. The AFM view also shows very smooth surface and controlled GaNovergrowth. The GaN buffer thickness is reduced comparing to thethickness of the GaN buffer stack grown on planar substrate 1701depicted in FIG. 17A. In an embodiment, the GaN buffer thickness isabout 1.1 microns.

FIG. 18A is a top view 1800 showing a III-V material stack structuregrown on a planar substrate 1801 according to one embodiment. Thisstructure has defect density of about 4×10⁹ cm⁻². FIG. 18B is a top view1802 showing a III-V material stack structure grown on mesa structuresaccording to one embodiment. This structure has crack free regions 1803and 1804. As shown in FIG. 18B, by laterally overgrowing GaN materialusing the silicon mesas, crack free regions are created, and thinner GaNstacks are formed.

FIG. 18C is a graph 1820 showing a current 1801 versus a voltage 1812curves for a GaN transistor grown using silicon mesas according to oneembodiment. Graph 1820 illustrates a body leakage current curve 1813, agate current curve 1814, and a source current curve 1815. As shown inFIG. 18C, a body leakage current 1813 of the GaN transistor grown usingsilicon mesas is very low (e.g., less than 1×10⁻¹² A).

FIG. 19A shows a cross-sectional view 1901 similar to FIG. 12 todemonstrate seamless merging of the LEO portions of the III-V materiallayer according to one embodiment. As shown in FIG. 19A, a portion 1902of the structure includes an LEO portion of the GaN layer formed overthe SiO₂ layer between the mesa structures. FIG. 19B is a top view 1903of the portion 1902 made by a scanning electron microscope (“SEM”). TheSEM view shows the laterally overgrown GaN 1902 with seamless merging.The squares 1904 show the windows from where GaN grows out. FIG. 19C isan atomic force microscope (“AFM”) image 1904 of a top view 1920 of thestructure having the portions of the GaN material laterally grown overan insulating layer between silicon mesas according to one embodiment.As shown in FIG. 19C, two LEO portions of GaN material formed betweentwo mesas are seamlessly merged into a single portion 1905.

FIG. 20 illustrates a computing device 2000 in accordance with oneembodiment. The computing device 2000 houses a board 2002. The board2002 may include a number of components, including but not limited to aprocessor 2001 and at least one communication chip 2004. The processor2001 is physically and electrically coupled to the board 2002. In someimplementations at least one communication chip is also physically andelectrically coupled to the board 2002. In further implementations, atleast one communication chip 2004 is part of the processor 2001.

Depending on its application, computing device 2000 may include othercomponents that may or may not be physically and electrically coupled tothe board 2002. These other components include, but are not limited to,a memory, such as a volatile memory 2008 (e.g., a DRAM), a non-volatilememory 2010 (e.g., ROM), a flash memory, a graphics processor 2012, adigital signal processor (not shown), a crypto processor (not shown), achipset 2006, an antenna 2016, a display, e.g., a touchscreen display2017, a display controller, e.g., a touchscreen controller 2011, abattery 2018, an audio codec (not shown), a video codec (not shown), anamplifier, e.g., a power amplifier 2009, a global positioning system(GPS) device 2013, a compass 2014, an accelerometer (not shown), agyroscope (not shown), a speaker 2015, a camera 2003, and a mass storagedevice (such as hard disk drive, compact disk (CD), digital versatiledisk (DVD), and so forth) (not shown).

A communication chip, e.g., communication chip 2004, enables wirelesscommunications for the transfer of data to and from the computing device2000. The term “wireless” and its derivatives may be used to describecircuits, devices, systems, methods, techniques, communicationschannels, etc., that may communicate data through the use of modulatedelectromagnetic radiation through a non-solid medium. The term does notimply that the associated devices do not contain any wires, although insome embodiments they might not. The communication chip 2004 mayimplement any of a number of wireless standards or protocols, includingbut not limited to Wi-Fi (IEEE 802.11 family), WiMAX (IEEE 802.16family), IEEE 802.20, long term evolution (LTE), Ev-DO, HSPA+, HSDPA+,HSUPA+, EDGE, GSM, GPRS, CDMA, TDMA, DECT, Bluetooth, derivativesthereof, as well as any other wireless protocols that are designated as3G, 4G, 5G, and beyond. The computing device 2000 may include aplurality of communication chips. For instance, a communication chip2004 may be dedicated to shorter range wireless communications such asWi-Fi and Bluetooth and a communication chip 2036 may be dedicated tolonger range wireless communications such as GPS, EDGE, GPRS, CDMA,WiMAX, LTE, Ev-DO, and others.

In at least some embodiments, the processor 2001 of the computing device2000 includes an integrated circuit die having III-V devicesco-integrated with Si CMoS devices on a silicon wafer as describedherein. The integrated circuit die of the processor includes one or moredevices, such as transistors or metal interconnects as described herein.The term “processor” may refer to any device or portion of a device thatprocesses electronic data from registers and/or memory to transform thatelectronic data into other electronic data that may be stored inregisters and/or memory. The communication chip 2005 also includes anintegrated circuit die having III-V devices co-integrated with Si CMoSdevices on a silicon wafer according to the embodiments describedherein.

In further implementations, another component housed within thecomputing device 2000 may contain an integrated circuit die having III-Vdevices co-integrated with Si CMoS devices on a silicon wafer accordingto embodiments described herein.

In accordance with one implementation, the integrated circuit die of thecommunication chip includes one or more devices, such as transistors andmetal interconnects, as described herein. In various implementations,the computing device 2000 may be a laptop, a netbook, a notebook, anultrabook, a smartphone, a tablet, a personal digital assistant (PDA),an ultra mobile PC, a mobile phone, a desktop computer, a server, aprinter, a scanner, a monitor, a set-top box, an entertainment controlunit, a digital camera, a portable music player, or a digital videorecorder. In further implementations, the computing device 2000 may beany other electronic device that processes data.

The following examples pertain to further embodiments:

A method to manufacture an electronic device comprising conformallydepositing an insulating layer on a plurality of mesa structures in atrench on a substrate to fill a space outside the mesa structures;depositing a nucleation layer on the mesa structures; and depositing aIII-V material layer on the nucleation layer, wherein the III-V materiallayer is laterally grown over the insulating layer.

A method to manufacture an electronic device comprising depositing aninsulating layer on a plurality of mesa structures in a trench on asubstrate, the insulating layer filling a space outside the mesastructures; depositing a nucleation layer on the mesa structures;depositing a III-V material layer on the nucleation layer, wherein theIII-V material layer is laterally grown over the insulating layer; anddepositing a device layer on the laterally grown III-V material layer.

A method to manufacture an electronic device comprising depositing aninsulating layer on a plurality of mesa structures in a trench on asubstrate, the insulating layer filling a space outside the mesastructures; depositing a nucleation layer on the mesa structures; anddepositing a III-V material layer on the nucleation layer, wherein theIII-V material layer is laterally grown over the insulating layer, andwherein the III-V material layer includes GaN, and the substrateincludes silicon.

A method to manufacture an electronic device comprising depositing aninsulating layer on a plurality of mesa structures in a trench on asubstrate, the insulating layer filling a space outside the mesastructures; depositing a nucleation layer on the mesa structures; anddepositing a III-V material layer on the nucleation layer, wherein theIII-V material layer is laterally grown over the insulating layer,wherein the insulating layer includes silicon oxide, silicon nitride, ora combination thereof.

A method to manufacture an electronic device comprising depositing aninsulating layer on a plurality of mesa structures in a trench on asubstrate, the insulating layer filling a space outside the mesastructures; depositing a nucleation layer on the mesa structures; anddepositing a III-V material layer on the nucleation layer, wherein theIII-V material layer is laterally grown over the insulating layer,wherein the nucleation layer includes AlN.

A method to manufacture an electronic device comprising depositing aninsulating layer on the substrate; patterning the insulating layer onthe substrate; etching the substrate through the patterned insulatinglayer to form a trench; depositing an insulating layer on a plurality ofmesa structures within the trench on the substrate filling a spaceoutside the mesa structures; depositing a nucleation layer on the mesastructures; and depositing a III-V material layer on the nucleationlayer, wherein the III-V material layer is laterally grown over theinsulating layer outside the mesa structures.

A method to manufacture an electronic device comprising depositing ahard mask layer in a trench on a substrate; patterning the hard masklayer; etching the substrate through the patterned hard mask layer toform a plurality of mesa structures; removing the hard mask layer;depositing an insulating layer on the plurality of mesa structureswithin the trench on the substrate, the insulating layer filling a spaceoutside the mesa structures; depositing a nucleation layer on the mesastructures; and depositing a III-V material layer on the nucleationlayer, wherein the III-V material layer is laterally grown over theinsulating layer outside the mesa structures.

A method to manufacture an electronic device comprising depositing aninsulating layer on a plurality of mesa structures in a trench on asubstrate, the insulating layer filling a space outside the mesastructures; depositing a nucleation layer on the mesa structures; anddepositing a III-V material layer on the nucleation layer, wherein theIII-V material layer is laterally grown over the insulating layer,wherein the distance between the mesa structures is determined by thelateral overgrowth rate of the III-V material layer.

A method to manufacture an electronic device comprising depositing aninsulating layer on a plurality of mesa structures in a trench on asubstrate, the insulating layer filling a space outside the mesastructures; depositing a nucleation layer on the mesa structures; anddepositing a III-V material layer on the nucleation layer, wherein theIII-V material layer is laterally grown over the insulating layer, andwherein the insulating layer covers a sidewall of the trench.

A method to manufacture an electronic device comprising depositing aninsulating layer on a plurality of mesa structures in a trench on asubstrate, the insulating layer filling a space outside the mesastructures; depositing a nucleation layer on the mesa structures; anddepositing a III-V material layer on the nucleation layer, wherein theIII-V material layer is laterally grown over the insulating layer, andwherein the III-V material layer grows faster over the insulating layerthan over the nucleation layer.

A method to manufacture an electronic device comprising depositing aninsulating layer on a plurality of mesa structures in a trench on asubstrate, the insulating layer filling a space outside the mesastructures; depositing a nucleation layer on the mesa structures; anddepositing a III-V material layer on the nucleation layer, wherein theIII-V material layer is laterally grown over the insulating layer, andwherein at least one of the mesa structures has a square shape;rectangular shape, or a polygon shape.

A method to manufacture an electronic device comprising depositing aninsulating layer on a plurality of mesa structures in a trench on asubstrate, the insulating layer filling a space outside the mesastructures; depositing a nucleation layer on the mesa structures; anddepositing a III-V material layer on the nucleation layer, wherein theIII-V material layer is laterally grown over the insulating layer, andwherein the size of at least one of the mesa structures is from 2microns to 10 microns.

A method to manufacture an electronic device comprising depositing aninsulating layer on a plurality of mesa structures in a trench on asubstrate, the insulating layer filling a space outside the mesastructures; depositing a nucleation layer on the mesa structures; anddepositing a III-V material layer on the nucleation layer, wherein theIII-V material layer is laterally grown over the insulating layer, andwherein the laterally grown III-V material layer is separated from theinsulating layer by a space.

An apparatus to manufacture an electronic device comprising aninsulating layer on a plurality of mesa structures in a trench on thesubstrate, the insulating layer filling a space outside the mesastructures; a nucleation layer on the mesa structures; and a III-Vmaterial layer on the nucleation layer, wherein the III-V material layeris laterally grown over the first insulating layer.

An apparatus to manufacture an electronic device comprising aninsulating layer on a plurality of mesa structures in a trench on thesubstrate, the insulating layer filling a space outside the mesastructures; a nucleation layer on the mesa structures; and a III-Vmaterial layer on the nucleation layer, wherein the III-V material layeris laterally grown over the first insulating layer; and a device layeron the laterally grown III-V material layer.

An apparatus to manufacture an electronic device comprising aninsulating layer on a plurality of mesa structures in a trench on thesubstrate, the insulating layer filling a space outside the mesastructures; a nucleation layer on the mesa structures; and a III-Vmaterial layer on the nucleation layer, wherein the III-V material layeris laterally grown over the first insulating layer, and wherein theIII-V material layer includes GaN, and the substrate includes silicon.

An apparatus to manufacture an electronic device comprising aninsulating layer on a plurality of mesa structures in a trench on thesubstrate, the insulating layer filling a space outside the mesastructures; a nucleation layer on the mesa structures; and a III-Vmaterial layer on the nucleation layer, wherein the III-V material layeris laterally grown over the first insulating layer, an wherein theinsulating layer includes silicon oxide, silicon nitride, or acombination thereof.

An apparatus to manufacture an electronic device comprising aninsulating layer on a plurality of mesa structures in a trench on thesubstrate, the insulating layer filling a space outside the mesastructures; a nucleation layer on the mesa structures; and a III-Vmaterial layer on the nucleation layer, wherein the III-V material layeris laterally grown over the first insulating layer, and wherein thenucleation layer includes AlN.

An apparatus to manufacture an electronic device comprising aninsulating layer on a plurality of mesa structures in a trench on thesubstrate, the insulating layer filling a space outside the mesastructures; a nucleation layer on the mesa structures; and a III-Vmaterial layer on the nucleation layer, wherein the III-V material layeris laterally grown over the first insulating layer, and wherein thedistance between the mesa structures is determined by the lateralovergrowth rate of the III-V material layer.

An apparatus to manufacture an electronic device comprising aninsulating layer on a plurality of mesa structures in a trench on thesubstrate, the insulating layer filling a space outside the mesastructures; a nucleation layer on the mesa structures; and a III-Vmaterial layer on the nucleation layer, wherein the III-V material layeris laterally grown over the first insulating layer, and wherein theinsulating layer covers a sidewall of the trench.

An apparatus to manufacture an electronic device comprising aninsulating layer on a plurality of mesa structures in a trench on thesubstrate, the insulating layer filling a space outside the mesastructures; a nucleation layer on the mesa structures; and a III-Vmaterial layer on the nucleation layer, wherein the III-V material layeris laterally grown over the first insulating layer, and wherein at leastone of the mesa structures is aligned along {0001} crystal orientation.

An apparatus to manufacture an electronic device comprising aninsulating layer on a plurality of mesa structures in a trench on thesubstrate, the insulating layer filling a space outside the mesastructures; a nucleation layer on the mesa structures; and a III-Vmaterial layer on the nucleation layer, wherein the III-V material layeris laterally grown over the first insulating layer, and wherein at leastone of the mesa structures has a square shape; rectangular shape, or apolygon shape.

An apparatus to manufacture an electronic device comprising aninsulating layer on a plurality of mesa structures in a trench on thesubstrate, the insulating layer filling a space outside the mesastructures; a nucleation layer on the mesa structures; and a III-Vmaterial layer on the nucleation layer, wherein the III-V material layeris laterally grown over the first insulating layer, and wherein thewidth of at least one of the mesa structures is from 2 microns to 10microns and wherein the height of at least one of the mesa structures isfrom 100 nanometers to 200 nanometers.

An apparatus to manufacture an electronic device comprising aninsulating layer on a plurality of mesa structures in a trench on thesubstrate, the insulating layer filling a space outside the mesastructures; a nucleation layer on the mesa structures; and a III-Vmaterial layer on the nucleation layer, wherein the III-V material layeris laterally grown over the first insulating layer, and wherein thelaterally grown III-V material layer is separated from the insulatinglayer by a space height of at least one of the mesa structures is from100 nanometers to 200 nanometers.

A method to manufacture an electronic device comprising forming aplurality of mesa structures within a trench on a substrate; conformallydepositing a first insulating layer within the trench; depositing anucleation layer on the mesa structures; depositing a III-V materiallayer on the nucleation layer; and laterally growing the III-V materiallayer from the nucleation layer over the first insulating layer.

A method to manufacture an electronic device comprising forming aplurality of mesa structures within a trench on a substrate; conformallydepositing a first insulating layer within the trench; depositing anucleation layer on the mesa structures; depositing a III-V materiallayer on the nucleation layer; and laterally growing the III-V materiallayer from the nucleation layer over the first insulating layer; anddepositing a device layer on the laterally grown III-V material layer.

A method to manufacture an electronic device comprising forming aplurality of mesa structures within a trench on a substrate; conformallydepositing a first insulating layer within the trench; depositing anucleation layer on the mesa structures; depositing a III-V materiallayer on the nucleation layer; and laterally growing the material layerfrom the nucleation layer over the first insulating layer, wherein theIII-V material layer grows faster over the first insulating layer thanover the nucleation layer.

A method to manufacture an electronic device comprising forming aplurality of mesa structures within a trench on a substrate; conformallydepositing a first insulating layer within the trench; depositing anucleation layer on the mesa structures; depositing a III-V materiallayer on the nucleation layer; and laterally growing the material layerfrom the nucleation layer over the first insulating layer, whereinforming the plurality of mesa structures comprises depositing a masklayer in the trench; patterning the mask layer; and etching thesubstrate through the patterned mask layer.

A method to manufacture an electronic device comprising forming aplurality of mesa structures within a trench on a substrate; conformallydepositing a first insulating layer within the trench; depositing anucleation layer on the mesa structures; depositing a III-V materiallayer on the nucleation layer; and laterally growing the material layerfrom the nucleation layer over the first insulating layer, wherein thelaterally grown III-V material layer is in a direct contact with thefirst insulating layer.

A method to manufacture an electronic device comprising forming aplurality of mesa structures within a trench on a substrate; conformallydepositing a first insulating layer within the trench; depositing anucleation layer on the mesa structures; depositing a III-V materiallayer on the nucleation layer; and laterally growing the material layerfrom the nucleation layer over the first insulating layer, wherein atleast one of the mesa structures has a square shape; rectangular shape,or a polygon shape.

A method to manufacture an electronic device comprising forming aplurality of mesa structures within a trench on a substrate; conformallydepositing a first insulating layer within the trench; depositing anucleation layer on the mesa structures; depositing a III-V materiallayer on the nucleation layer; and laterally growing the material layerfrom the nucleation layer over the first insulating layer, wherein theIII-V material layer is separated from the insulating layer by a space.

What is claimed is:
 1. An electronic device, comprising a mesa structure having a top surface and a sidewall on a substrate; a first insulating layer on the sidewall of the mesa structure; a III-V material layer on the top surface of the mesa structure, wherein the III-V material layer has a lateral epitaxial overgrowth portion on the first insulating layer.
 2. The electronic device of claim 1, further comprising a nucleation layer on the top portion of the mesa structure.
 3. The electronic device of claim 1, further comprising a device layer on the lateral epitaxial overgrowth portion.
 4. The electronic device of claim 1, wherein the III-V material layer includes GaN and the mesa structure includes silicon.
 5. The electronic device of claim 1, wherein the first insulating layer includes silicon oxide, silicon nitride, or a combination thereof.
 6. The electronic device of claim 1, wherein the mesa structure is within a trench in a second insulating layer on the substrate.
 7. The electronic device of claim 1, wherein the mesa structure is aligned along a {0001} crystal orientation.
 8. The electronic device of claim 1, wherein the mesa structure has a square shape; rectangular shape, or a polygon shape.
 9. The electronic device of claim 1, wherein the lateral epitaxial overgrowth portion layer is in direct contact with the first insulating layer.
 10. The electronic device of claim 1, wherein a bottom surface of the laterally extended III-V material layer is not in direct contact with the insulating layer.
 11. The electronic device of claim 1, wherein the size of at least one of the mesa structures is from 2 microns to 10 microns.
 12. A system comprising: a chip including an electronic device comprising a mesa structure having a top surface and a sidewall on a substrate; a first insulating layer on the sidewall of the mesa structure; a III-V material layer on the top surface of the mesa structure, wherein the III-V material layer has a lateral epitaxial overgrowth portion on the first insulating layer.
 13. The system of claim 12, further comprising a nucleation layer on the top portion of the mesa structure.
 14. A method to manufacture an electronic device comprising: forming a mesa structure comprising a top surface and a sidewall on a substrate; depositing a first insulating layer on the sidewall of the mesa structure; depositing a III-V material layer on the top surface of the mesa structure; and laterally growing the III-V material layer from the top surface over the first insulating layer.
 15. The method of claim 14, further comprising depositing a nucleation layer on the top surface of the mesa structure.
 16. The method of claim 14, further comprising depositing a device layer on the laterally grown III-V material layer.
 17. The method of claim 14, wherein forming the mesa structure comprises depositing a mask layer in a trench in a second insulating layer on the substrate; patterning the mask layer; and etching the substrate through the patterned mask layer.
 18. The method of claim 14, wherein the laterally grown III-V material layer is in a direct contact with the first insulating layer.
 19. The method of claim 14, wherein the III-V material layer is separated from the first insulating layer by a space.
 20. The method of claim 14, further comprising depositing a second insulating layer on the substrate; patterning the second insulating layer; etching the substrate through the patterned second insulating layer to form the trench. 